Finally got the P0A80 on my 2011

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by koukilights, Feb 23, 2025 at 4:52 PM.

  1. koukilights

    koukilights Junior Member

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    2011 with 315k miles and I finally got the P0A80 on my original battery pack.

    I cleared the code with my generic scanner and drove the 15 miles home and it hasn't come back on yet.

    From what I've read, this is a code indicating I have a voltage difference between a few cells in the pack. What scanner can I get to monitor individual cell voltages? Techstream? Some sort of android to bluetooth obd2 scanner software?

    How long can I drive on it like this?

    What are my options to fix this? Are there aftermarket new-style cell packs that don't cost an arm and leg?
     
    #1 koukilights, Feb 23, 2025 at 4:52 PM
  2. JC91006

    JC91006 Senior Member

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    A 14 year old battery pack is already on it's last legs and should be replaced. Instead of finding a rebuilder, you should call around to local salvage/wrecking yards and see if they have a late model hybrid with similar modules you can buy. Then swap in the newer modules. This will be the best economical and reliable solution
     
    #2 JC91006, Feb 23, 2025 at 6:11 PM
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  3. koukilights

    koukilights Junior Member

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    I've tried rebuilding/replacing modules and balancing them back in my 2nd gen prius. And it never worked. I just kept getting the P0A80 code every other week. It was like wackamole.
     
    #3 koukilights, Feb 23, 2025 at 8:32 PM
  4. bisco

    bisco cookie crumbler

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    aftermarket are similarly priced to oem, around 2k.
     
    #4 bisco, Feb 23, 2025 at 8:39 PM
  5. JC91006

    JC91006 Senior Member

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    You need to have a little skill in determining the bad modules in the pack and replacing them. If you cannot do that properly, you can buy a complete used pack from a salvage yard and put it in your car.

    That should work if it's not old
     
    #5 JC91006, Feb 23, 2025 at 8:39 PM
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  6. koukilights

    koukilights Junior Member

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    That's brand new OEM? Or refurbished/used oem packs?
     
    #6 koukilights, Feb 23, 2025 at 9:07 PM
  7. koukilights

    koukilights Junior Member

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    How do you determine the bad cells? If I remember from my 2nd gen rebuild, it was a matter of putting a smal load on the cell like a light bulb, and measuring the voltage and seeing which ones were lower than the others.

    But I could either never get all the bad cells, or perhaps the "new" cells weren't balanced properly to the pack? I don't know what exactly went wrong.

    I'm open to replacing a few cells if that would work, but I remember trying to do that, still getting the CEL, and juts buying an entire replacement pack in the end.
     
    #7 koukilights, Feb 23, 2025 at 9:09 PM
  8. bisco

    bisco cookie crumbler

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    brand new oem. call all the dealers you are willing to drive to, they are competitive
     
    #8 bisco, Feb 23, 2025 at 9:11 PM
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  9. MAX2

    MAX2 Active Member

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    Your answers are contradictory. You claim that you repaired the high-voltage battery, but you do not know how to identify bad cells. Then what is the point of repairing? Rearranging the faulty and working ones in different places. But the sum does not change from rearranging the terms.
     
    #9 MAX2, Feb 24, 2025 at 1:20 AM
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  10. JC91006

    JC91006 Senior Member

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    There are many factors to determine if you would get a successful rebuild. It probably would help if the battery pack that you are repairing is an original pack containing most of the original modules. For example in a pack of 28 modules, you would want at least 25 of them to be the same, replacing maybe up to 3 failed modules of similar capacity and age. This will allow you to get the best results for reliability.

    If you are rebuilding a battery pack with many different modules of different age and capacities, you will have a hard time to get a reliable pack. The computer in the car will pick up the differences in voltage under load (100a) so if the modules are not very similar, you will get a failure again.

    Internal resistance in a module, the self discharge rate, voltage variations, etc all will determine how long the battery pack will last you. So you really need a little bit of skill and experience before you can properly rebuild a battery pack
     
    #10 JC91006, Feb 24, 2025 at 1:47 AM
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  11. koukilights

    koukilights Junior Member

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    Yes, on my 2nd gen prius, I replaced cells that I thought were bad. Ones that had lower voltage without a load, and doubled checked to have lower voltage with a light bulb on it as a simulated load. It didn't work and I ended up just getting a replacement pack altogether.

    So, I have replaced/repaired a HV batt, but either I had bad luck or I don't really know how to identify bad cells. Which is why I'm asking here.

    Does that make it more clear?
     
    #11 koukilights, Feb 24, 2025 at 2:37 AM
  12. MAX2

    MAX2 Active Member

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    A cell can have different voltages depending on how charged it is.

    What is low voltage in your understanding? 8v? 7v? 6v?
     
    #12 MAX2, Feb 24, 2025 at 2:50 AM
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